Jailbroken iPhone 3G - can't restore...??

Hi all,

I have spent a lot of time trying to restore an old iPhone 3G, which was Jailbroken using redsn0w (I think) some long time ago. Well, I decided to erase all setting and now am stuck at the restore from iTunes screen.

I have tried to download a few customised IPSW's but can't seem to find the right one..

I know I haven't given much info. as I am not sure what I need to know to get it back working again, hence the post.

So, any help would be really usefull.

Thanks in advance..

What error message # does iTunes give you after the restore fails?

Sorry for the delay in getting back.

The message says: The iPhone could not be restored. An unknown error occured (1015). I have looked up this on the internet and it's about backwards compatibility I think but I now can't find the right ipsw to make it work again!!